# Thread: Logic question - MDX - placing nodes correctly?

1. ## Logic question - MDX - placing nodes correctly?

Originally Posted by 2k1Toaster
...
Make a Brain, make an Analogue to your temp sensor, make a variable (numeric).

Then make the following if statement:

...
<I didn't want to hijack -zip-'s thread more than I have already, and I'm not sure if this would clutter the tutorial so...>

I need help thinking in fusion logic terms.

Can you please explain what the green arrow does here? What exactly does it represent?

For me, looking at it, it looks like this function assigns the voltage value of the analog input to Evaluated_Temperature, then converts it to Temperature C, and then to F, then the green arrow being there for the right side of the node if this function is used elsewhere (input to another node, maybe as a custom function). So in looking at it, I would think that Evaluated_Temperature in this case would be over by the arrow, after the conversion.

The error message that shows when I try to link the output node to the CtoF function's output, leads me to believe that the output is infact the result of the outer If/then statement, which has no meaning I assume if this loop isn't nested in another one, the function evaluation just moves to the next "root function".

Doing it the way I initially thought it goes, gives an Invalid Node Link error though.

It just seems backwards to me... and I don't want to carry this errored thinking into more functions.
thx.

2. The way you think is right, is right. The image I posted is actually incorrect. I blame it on being burnt out.

But if you want a more detailed answer other than you are right and that reference is wrong, here it is:

when the if/then is evaluated is starts at the output and works inwards. It is a recursive function. So it looks at the main node, then its child nodes until there are no more children. So it evaluates the furthest nested node first. So with the variable-set, everything before it gets stored in the variable. So in what you are trying to do is correct.

The problem is the configurator checked if it was a variable or not, and if it was a boolean or numeric varaible. This is all fine and dandy for varaible-get modules, but variable-set modules are "typeless" so to speak as in they just pass through the previous value, and the configurator was not checking for this. It is now though and you can link it the proper way now.

I guess I can test out my updater.

3. Also I just noticed I was missing a tag in the main MDX program relating to this, so the new version I am uploading now will fix both these issues.

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